Dtc C0278 Open In Abs Solenoid Relay Circuit

Brake. Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35
Brake Control. Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT SKID CONTROL ECU (+BS TERMINAL)

INSPECT SKID CONTROL ECU (GND1 TERMINAL)

RECONFIRM DTC

DTC C0278 Open in ABS Solenoid Relay Circuit

DTC C0279 Short in ABS Solenoid Relay Circuit


DESCRIPTION

The solenoid relay supplies power to the ABS solenoids and TRC solenoids.
The solenoid relay is turned on 1.5 seconds after the ignition switch is turned to ON, and is turned off if an open or short in the solenoid is detected by self diagnosis performed when the vehicle starts running.
The solenoid relay is housed in the skid control ECU in the actuator assembly.

DTC Code
DTC Detection Condition
Trouble Area
C0278
Either of the following is detected:
  1. Both of the following conditions continue for 0.2 seconds or more.
    1. The IG1 terminal voltage is 9.5 V or higher.
    2. The solenoid relay contact is open when the relay is on.
  2. Both of the following conditions continue for 0.2 seconds or more.
    1. The IG1 terminal voltage becomes below 9.5 V when the relay is turned on.
    2. The relay contact remains open.
  1. ABS2 H-fuse
  2. Solenoid relay circuit
  3. Brake actuator assembly (solenoid relay)
C0279
Immediately after the ignition switch is turned to ON, the solenoid relay contact is closed for 4 seconds when the relay is turned off.
  1. Solenoid relay circuit
  2. Brake actuator assembly (solenoid relay)

WIRING DIAGRAM

Refer to DTCs C0226, C0236, C0246, C0256 and C1225 (RAV4_ACA30 RM000000XI8042X_02.html).

INSPECTION PROCEDURE

NOTICE:
  1. Inspect the fuses for circuits related to this system before performing the following inspection procedure.
  2. When replacing the brake actuator assembly, perform zero point calibration (RAV4_ACA30 RM000001K1O00SX.html).
HINT:
When C1241 and/or C1417 is output together with C0278 and/or C0279, inspect and repair the trouble areas indicated by C1241 and/or C1417 first (RAV4_ACA30 RM000000XW6048X.html or RAV4_ACA30 RM00000368W00BX.html).
1.INSPECT SKID CONTROL ECU (+BS TERMINAL)


    Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35.Brake Control.Anti-Lock Brake System. Dtc C0278 Open In Abs Solenoid Relay Circuit

  1. Make sure that there is no looseness in the locking part and connecting part of the connectors.

  1. Disconnect the skid control ECU connector.

  1. Measure the voltage according to the value(s) in the table below.

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    A67-12 (+BS) - Body ground
    		Always
    		11 to 14 V


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (+BS CIRCUIT)
OK


2.INSPECT SKID CONTROL ECU (GND1 TERMINAL)


    Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35.Brake Control.Anti-Lock Brake System. Dtc C0278 Open In Abs Solenoid Relay Circuit

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A67-1 (GND1) - Body ground
    		Always
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 CIRCUIT)
OK


3.RECONFIRM DTC
HINT:
This code is stored when a problem is identified in the brake actuator assembly.
The solenoid circuit is in the brake actuator assembly.
Therefore, solenoid circuit inspection and solenoid unit inspection cannot be performed. Be sure to check if the DTC is output before replacing the brake actuator assembly.

  1. Reconnect the skid control ECU connector.

  1. Clear the DTCs (RAV4_ACA30 RM000000ONJ027X.html).

  1. Start the engine.

  1. Drive the vehicle at a speed of 20 km/h (12 mph) or more for 30 seconds or more.

  1. Check if the same DTC is output (RAV4_ACA30 RM000000ONJ027X.html).

    Result:

    Result
    		Proceed to
    DTCs (C0278 and C0279) are not output.
    		A
    DTCs (C0278 and/or C0279) are output.
    		B
    HINT:
    1. If a speed signal of 6 km/h (4 mph) or more is input to the skid control ECU with the ignition switch ON and the stop light switch off, the ECU performs self diagnosis of the motor and solenoid circuits.
    2. If the normal system code is output (no trouble codes are output), slightly jiggle the connectors, wire harnesses, and fuses of the brake actuator assembly. Make sure that no DTCs are output.
    3. If any DTCs are output while jiggling a connector or wire harness of the brake actuator assembly (skid control ECU), inspect and repair the connector or wire harness.
    4. It is suspected that the DTCs were output due to a bad connection of the connector terminal.


B
REPLACE BRAKE ACTUATOR ASSEMBLY (RAV4_ACA30 RM000001XV200PX.html)
A

CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) (RAV4_ACA30 RM00000135201PX.html)